Measuring level of metal melt below liquid slag - by probe with partly shielded resistance bridge contacts shielded by sacrificial cap

摘要

The arrangement is intended for gauging the level of molten metal below a layer of liquid slag in a metallurgical vessel, using a probe with two contacts (4,5) which are connected (6,7) to a circuit, e.g. a resistance bridge, responding to the transition as the contacts pass the interface between the two liquids. The contacts are shielded by a cap (9,10) and the probe is rapidly immersed through the slag into the metal where this cap disintegrates. The measurement is then carried out as the probe is withdrawn. The contacts extend approximately vertically and are each covered to near their extreme ends by a high-melting sheath, e.g. a quartz glass tube (8). Used for gauging level of molten metal below molten slag layer in process vessel. The arrangement prevents the irregularities in the electrical resistance of the slag from interfering with the measurement which occurs when this is carried out during insertion of a probe with unshielded contacts into the melt. The sheathing of the contacts produces a clearly defined transition signal during withdrawal.